Various types of foundations are already known for erecting loading structures such as buildings or embankments for a highway. It is especially known to dispose piles in the ground above which the building is erected. Traditionally, a network of beams made of traditional reinforced concrete is then disposed at the top of the piles to support the floor of the loading structure, or the floor of such structure to which the piles are connected is designed as a slab able to sustain the local stresses generated by the supporting piles. If the piles are disposed in a mechanically weak ground, the load induced by the building is essentially transmitted by the piles to a harder deeper layer of the ground. Thus, substantially no charge of the building is transmitted to the weak ground and the piles must be designed to support 100% of the load of the building, leading to larger pile diameters and higher ratio of steel reinforcement in the piles. In addition, this generates high stresses and bending moments in the beams or slab above, requiring them to have a greater thickness.
To avoid these issues, it is also known to use rigid or semi-rigid inclusions, called “Controlled Modulus Columns” (CMCs). These inclusions have been used for decades to improve soils and control settlement of structures and embankments. CMCs are semi-rigid, cylindrical concrete columns typically installed in the soil with a hollow-stem lateral-displacement auger.
A plurality of such inclusions is generally disposed in the ground. A load transmitting layer is interposed between the ground and the load structure disposed thereon. As a result, only between 50% and 80% of the load of the supported structure is transmitted to the inclusions through the load transmitting layer, leading to smaller diameters for the inclusions and reduced stresses in the beams or slab supporting the loading structure.
U.S. Pat. No. 6,672,015 discloses a device for reinforcing a ground on which is disposed a loading structure, comprising a series of structural inclusions installed in the ground with a lateral-displacement auger and configured to mechanically reinforce said ground. The inclusions present a constant-diameter cylindrical shape.